Trematodes And Cestodes Flashcards Preview

Parasitology > Trematodes And Cestodes > Flashcards

Flashcards in Trematodes And Cestodes Deck (67):
0

Characteristics of digametic trematodes

Covered with syncytium
Typically hermaphroditic
2 suckers, anterior and a posterior
All lay eggs

1

What group of animals are the final and intermediate hosts of digenetic trematodes

Vertebrate final host
Mollusk intermediate host - snail

2

What developmental stages found in the snail

Sporocysts
Daughter sporocysts
Redia
Cercaria (infective to vertebral host)

3

Characterize trematodes transmission

With exception of schistosomes, all transmission of trematodes is via ingestion of the Cercaria stage

4

Which flukes are transmitted via ingestion of vegetation

Fasciolopsis buski - giant intestinal fluke
Fasciola hepatica - sheep liver fluke
Fascioloides magna
Peramphistomes

5

What are the vertebrate hosts of Fasciolopsis buski

Pigs and humans (small intestine)

6

How are people infected and affected by Fasciolopsis buski

Peeling water chestnuts and buffalo nuts with their teeth - ingest metacercarial cyst
Usually no damage with small infections... May see edema of face, intestinal obstruction

7

In what specific site are Fasciola hepatica found

Bile duct of sheep and cattle

8

What causes disease in Fasciola hepatica infection

Larvae leave ingesting, come out through wall, burrow through liver to get to bile duct

9

Distinguishing feature about Fasciola hepatica cercaria

They have a tail

10

What site specific place are Fascioloides magna found I

Cysts in liver of white tailed deer

11

How do Fascioloides magna affect sheep cattle and bison

Sheep - leave dark pigment when destroying liver
Cattle - do not find eggs in feces
Bison - refractory to infection

12

How do peramphosomes cause pathology

Immature flukes burrow into wall of small intestine effort making their way back to the rumen where they live (or cecum/colon in hind gut fermenters)

13

Which trematodes are transmitted via ingestion of insects

Dicrocoelium dendriticum - lanceolate liver fluke
Eurytrema pancreaticum/procyonis

14

What vertebrates can Dicrocoelium dendriticum be found in, and in what organ
What insect must be ingested

Sheep, deer, woodchucks, cattle, pigs
Bile duct
Ants

15

What age range of animals are pathological with Dicrocoelium dendriticum infection

Older animals, must be within animals for a ling time to see pathology

16

Which trematodes are transmitted via consumption of crayfish and crabs

Paragonimus kellicotti

17

In what hosts and where within the hosts do Paragonimus kellicotti live

Mink and bobcats naturally, also can infect dogs and cats
Live in cysts in the lungs (larva migrate straight throughout diaphragm to lungs)

18

Which trematodes transmitted via ingestion of fish

Nanophyetus samlincola
Clonorchis sinensis
Opisthorchis
Metorchis

19

What hosts are adult Nanophyetus salmincola found in

Bear raccoon coyote mink other canids

20

What agent does Nanophyetus salmincola vector and what is the associated disease

Nerickettsia helminthoeca
Mostly fatal diarrhea and vomiting in dogs

21

What fish are sources of Nanophyetus salmincola

Rainbow trout and steelhead trout

22

What is the common name for Clonorchis sinensis

Oriental liver fluke

23

What are common vertebrate hosts of the oriental liver fluke

People in Asia, dogs

24

What is the vertebrate host of metorchis conjunctus

Cat, in bile duct

25

How is platynosum fastosum transmitted
What are the host and specific site within the host

Ingestion of lizards or frogs
Found I bile ducts or gall bladder of cats in the tropics

26

Alaria species are transmitted via various paratenic hosts. What are their vertebrate final hosts

Fox, raccoon, skunk, dog, cat
Live in intestine

27

What is another way to transmit Alaria besides ingestion of paratenic host

Passed through milk of cat

28

What stage of Alaria causes disease

Larva

29

How are hosts infected with schistosomatidae

Skin penetration

30

What does the name schistosomes imply?

Split bodies,... Separate males and females

31

What is the scientific name for the America schistosomes and how does it cause disease

Heterobilharzia americana
Adults live in veins but, Eggs carried to liver causing fibrosis

32

Why use saline when looking for the human parasite, Schistosoma mansoni

Eggs spontaneously hatch in fresh water and would no longer float

33

Distinguishing feature of Schistosomes cercariae

Forked tail

34

What causes death in Schistosoma japonicum infection in sheep

Huge liver and spleen cause esophageal vertices to rupture

35

Which schistosomes cause zoonotic schistosomes dermatitis

Avian schistosomes (via contaminated water)

36

How are Cestoda characterized

No gut (no exceptions), Segmented, White, Live in small intestines as adults, Hermaphroditic, anterior holdfast of some sort, lay eggs that are passed in feces of final host, Final host i
Infected by eating larva in intermediate host

37

Are segments of tapeworms older or youngest just behind the scolex

Youngest

38

What does each pro glottis of Cestoda usually have

Genital opening(s)
Both male and female reproductive parts

39

Distinguish between the two types of tapeworms

Anapolyitic - segments release eggs into feces
Apolytic - segments detach and pass out with feces before releasing eggs

40

What are 2 types of intermediate hosts of Diphyllobothriidea tapeworms

Copepod and vertebrate

41

What is scientific name for broad fish tapeworm
What does it parasitize

Diphyllobothriidium latum
Fish eating mammals

42

Life cycle of Diphyllobothridium latum

Operculate egg in feces
Out of egg comes coracidium
Ingested by copepod and becomes procercoid
After fish ingests copepod, becomes placeroid
Eventually develops into adult

43

Physical characteristics of Dyphillobothrium latum

No hooks or suckers on scolex, only small groove; medial uterus

44

What disease is associates with Diphyllobothriidium latum

B12 deficiency in Scandinavian women

45

What are the important host of Spirometra mansonoides
What is associated disease called

Final host is bobcat
Can use mammalian paratenic hosts - potentially zoonotic
Sparganosis

46

Characterize scolex of Cyclophyllidea

4 suckers

47

Key points about life cycle of Cyclophyllidia

Terrestrial, only 1 intermediate host

48

What type if animal is the second host of Mesocestoides

Vertebrates, often dogs

49

Common name for Dipylidium caninum

Flea tapeworm (a Cyclophyllidia)

50

Where are adult DIPYLIDIUM found, how was it transmitted
How are eggs deposited

Dog and cat, ingestion of infected flea
- segments crawl out to deposit eggs

51

Anoplocephalids are parasites of?
Intermediate hosts are?

Herbivores, typically not pathogenic
Free living arthropods

52

Genus of anoplocephala in sheep and cattle

Monieza (species in cattle have square eggs)

53

Which anoplocephala in horse and at what site

A. Magna in jejunum
A. Perfoliats at ileo-cecal junction (has really narrow segments)

54

Describe final host, intermediate host, physical characteristics and geographic distribution of Thysanosoma actinoides

Sheep
Booklice
Fringed segments
Western US

55

Describe larval stages of Taeniid tapeworms
Cystocercus
Strobilocercus
Coenurus
Hydatid

Cyctocercus - one head per bladder
Strobilocercus - one head per bladder, but has strobilization (segments)
Coerunus - multiple heads per bladder
Hydatid - thousands of heads per cyst (only Echinococcus)

56

How long does it take for Taenia segment to be shed

2 months

57

Canine Taenia species and their larval forms

T. Ovis - cysticercus in sheep
T. Multiceps - coenurus in sheep
T. Pisiformis - cysticercus in rabbit
T. Serialis - coenurus in rabbit
T. Hydantigena - cysticercus in ruminants
Foxes: T. Crassiceps - cysticercus in rodents

58

What is the feline Taenia species and their intermediate host

T. Taeniaeformis
Rats (strobilicercus)

59

What are human Taenia species, larval type and intermediate host

Taenia sanginata - cysticercus in beef muscle
T. Asiatica - cysticercus in swine
T. Solium - cysticercus in pork and in people

60

Distinguish between Taenia saginata and T. solium

T. Saginata scolex has no hooks or suckers, t. Solium has sucker and 2 rows of hooks.
Pro glottis of T. Saginata has more uterine branching than t. solium

61

Common name for Taenia asiatica

Pork liver tapeworm

62

Echinococcus larval stage

Hydatid

63

Two important Echinicoccus species in dogs

E. granulosus
E. multilocularis

64

Where do Echinococcus granulosus larvae usually migrate within the cervid intermediate host to form the hydatid cyst

How do the larva get into the int. host

Lungs

Eggs released in canid feces are ingested by cervids and hatch into larva

65

What is a protoscolex

Larval tapeworms that develop from the hydatid cyst

66

Where to Echinococcus multilocularis hydatids usually develop

Lungs of rodents